Test your boolean expression by hand: suppose character == 'X'; it most certainly isn't an 's' or 'd' or 't' so your boolean expression is true. You didn't have this in mind but what did you have in mind?

Try with a SWITCH statement. It may be a bit longer but at least you will be able to control what happenes with all of the alphabet letters. After you get itworking, try to change it to if else. That way you know what works and what doesnt. Thats
how I would do it